The present invention relates to an anchor. The principles of the invention can be applied to anchors of any size.
A problem which is often encountered when using an anchor is the inability to release an anchor which has become lodged or jammed on a submarine obstruction on the sea bed or river bed. Because a vessel, particularly a small boat can exert only a relatively small traction there is usually no alternative but to cut the anchor free and discard it. Anchors, however, are expensive items and this practice is wasteful and uneconomic. Considerable attention has been given to the problem of enabling release of a jammed anchor. The problem is exacerbated by the fact that satisfactory anchoring frequently actually requires that the anchor be lodged or jammed on something on the sea or river bed, so that anchors are shaped specifically in order to catch against any such obstruction. Obviously however, this engagement with a submarine obstruction should be releasable when it is desired no longer to hold the boat fast in a particular location to allow it to depart.
One prior art attempt to solve this problem has included the use of a secondary line between the boat and the chain, operative when pulled to raise the anchor and seek to change its orientation. In many circumstances, however, when the anchor blades or tines are lodged securely, particularly against rock or weed, no amount of tension on the secondary line can effect the necessary release.
Another attempt to solve this problem has involved the use of a slotted link connection between two parts of an anchor which are relatively movable. The theory in this case is that if the anchor is moving in one direction when it jams, then by sailing or driving the boat in the opposite direction and allowing the two relatively movable parts to slide along the slotted connection so that the opposite end of the slot is engaged, then release of the jammed part of the anchor may be effected. Again, in practice, this has been found to be impractical partly because of the force with which jamming can take place, and partly because the relatively fixed orientation of the jammed part means that a greater twisting force is applied to the anchor when the anchor chain is pulled in any but the original direction it was travelling in when the jamming took place, and, of course, it is totally impossible to release a jammed anchor by applying a greater tension in the original direction.